Paint.



To all whom it may concern:

UNITED STATES PATENT OFFICE.

HENRY HOWARD, 0F BOSTON, MASSACHUSETTS Patented J an. 20, 1914.

PAINT.

1,084,884. Specification of Letters Patent.

No Drawing. Application filed January 28, 1913. Serial No. 744,674.

Be it known that I, HENRY Howaun, a citizen of the United States,residiu at Boston, in the county of Suffolk and btate of Massachusetts,have invented certain new and useful Improvements in Paints, of

which the following is a. specification.

My invention relates to the manufacture of inhibitive paints, forpainting exposed iron-work, and for other general uses.

The object of my invention is to produce a paint which will protectiron, steel, etc.,

' from corrosion, and which will retard, if not entirely prevent, thefurther corrosion of iron and steel which has already rusted to agreater or less degree.

The base of the paint is the residue remaining from' thetreatment ofnative a1uminous compounds, such as bauxite, preferably red Frenchbauxite, by alkalis, to form sodium aluminate. This residue, known tosodium aluminate manufacturers and others as red mud, contains the partof the bauxite which is insoluble in the alkali; it contains, amongother substances, a sodium aluminum silicate, which, while substantiallyinsoluble in 'ater, has the property of combining with and neutralizingany weak acid, such as fatty acids in oil, carbonic acid in air, etc.This material, red mud, containing the sodiunraluminum-silicate,possesses inhibiting properties to a marked degree, and when suitablymixed with oils to form a paint, has the property of protecting iron andsteel from corrosion for a long time. If this paint is applied to arusted surface. even though the rust has not been entirely removed, theiron or steel is protected from tho spreading of the rust, as no furtherincrease of corrosion is noted even after a long period of time. Thisinhibiting action is supposed to be due to the fact that the paintmaintains a slightly alkaline condition on the surface of the iron for along time, during which the metal is protected from corrosion.

The paint is made as follows: The red mud contains a large quantity offinelydivided matter mixed with coarser particles.

The finely-divided part is separated preferably by flotation, the coarsepart being reected; or the coarse part may be separately ground and usedas a mixture in other paints to impart inhibitive qualities; or thecut-Ire mass may, if desired, be ground to a suitable degree offineness, and avoid separation. Thc finely-divided mass of red mud isbrought into suspension in oil, either by drying and grinding in oil, orby mixing 'the oil directly with the wet mass, in which base the oildisplaces the water, forming a paint mixture of oil and red mud. Thewater collecting above the paint may be drained oil, the last tracesbeing removed by heating if so desired. The oil paint mixture may bethinned if desired by a further addition of oil, or by any of the usualthinners. The paint so produced is applied as are other ordinary paints.

I claim:

1. A rust-inhibitive paint containing red mud, being the residue of thetreatment of native aluminous compounds with alkalis.

2. A rust-inhibitive aint containing an oxygen compound of SOt ium,aluminum and silicon, being the residue of the treatment of bauxite withalkalis.

3. A rust inhibitivc paint containing sodium-aluminum silicate, beingthe residue of the treatment of native aluminous compounds with alkalis.

4. A rust inhibitive paint containing sodium-aluminum silicate, beingthe residue of the treatment of bauxite with alkalis.

5. A rust-inhibitirc paint containing an artificial water-insolubleOxygen compound of sodium, aluminum and silicon mixed with oil.

(3. A rust-inhibitire paint. containing an artificial water-insolublesodium-aluminumsilicate mixed with oil.

In testimony-whereof I afiix my signature in presence of two witnesses.

HENRY HOWARD.

Witnesses:

I. M. GRAHAM, M. V. OBmnn.

